From e078b79d8aa70a48fb3fa684e6a6548c5127646b Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Tue, 18 Nov 2014 09:51:03 -0300 Subject: [PATCH] [media] vb2-dma-sg: add dmabuf import support Add support for importing dmabuf to videobuf2-dma-sg. Signed-off-by: Hans Verkuil Acked-by: Pawel Osciak Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/videobuf2-dma-sg.c | 151 ++++++++++++++++++++++++++--- 1 file changed, 137 insertions(+), 14 deletions(-) diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c index 346e39b..81e88a0 100644 --- a/drivers/media/v4l2-core/videobuf2-dma-sg.c +++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c @@ -41,11 +41,19 @@ struct vb2_dma_sg_buf { int offset; enum dma_data_direction dma_dir; struct sg_table sg_table; + /* + * This will point to sg_table when used with the MMAP or USERPTR + * memory model, and to the dma_buf sglist when used with the + * DMABUF memory model. + */ + struct sg_table *dma_sgt; size_t size; unsigned int num_pages; atomic_t refcount; struct vb2_vmarea_handler handler; struct vm_area_struct *vma; + + struct dma_buf_attachment *db_attach; }; static void vb2_dma_sg_put(void *buf_priv); @@ -112,6 +120,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, buf->size = size; /* size is already page aligned */ buf->num_pages = size >> PAGE_SHIFT; + buf->dma_sgt = &buf->sg_table; buf->pages = kzalloc(buf->num_pages * sizeof(struct page *), GFP_KERNEL); @@ -122,7 +131,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, if (ret) goto fail_pages_alloc; - ret = sg_alloc_table_from_pages(&buf->sg_table, buf->pages, + ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages, buf->num_pages, 0, size, GFP_KERNEL); if (ret) goto fail_table_alloc; @@ -147,7 +156,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, fail_map: put_device(buf->dev); - sg_free_table(sgt); + sg_free_table(buf->dma_sgt); fail_table_alloc: num_pages = buf->num_pages; while (num_pages--) @@ -171,7 +180,7 @@ static void vb2_dma_sg_put(void *buf_priv) dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); if (buf->vaddr) vm_unmap_ram(buf->vaddr, buf->num_pages); - sg_free_table(&buf->sg_table); + sg_free_table(buf->dma_sgt); while (--i >= 0) __free_page(buf->pages[i]); kfree(buf->pages); @@ -183,7 +192,11 @@ static void vb2_dma_sg_put(void *buf_priv) static void vb2_dma_sg_prepare(void *buf_priv) { struct vb2_dma_sg_buf *buf = buf_priv; - struct sg_table *sgt = &buf->sg_table; + struct sg_table *sgt = buf->dma_sgt; + + /* DMABUF exporter will flush the cache for us */ + if (buf->db_attach) + return; dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); } @@ -191,7 +204,11 @@ static void vb2_dma_sg_prepare(void *buf_priv) static void vb2_dma_sg_finish(void *buf_priv) { struct vb2_dma_sg_buf *buf = buf_priv; - struct sg_table *sgt = &buf->sg_table; + struct sg_table *sgt = buf->dma_sgt; + + /* DMABUF exporter will flush the cache for us */ + if (buf->db_attach) + return; dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); } @@ -221,6 +238,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, buf->dma_dir = dma_dir; buf->offset = vaddr & ~PAGE_MASK; buf->size = size; + buf->dma_sgt = &buf->sg_table; first = (vaddr & PAGE_MASK) >> PAGE_SHIFT; last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT; @@ -273,7 +291,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr, if (num_pages_from_user != buf->num_pages) goto userptr_fail_get_user_pages; - if (sg_alloc_table_from_pages(&buf->sg_table, buf->pages, + if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages, buf->num_pages, buf->offset, size, 0)) goto userptr_fail_alloc_table_from_pages; @@ -315,7 +333,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv) dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); if (buf->vaddr) vm_unmap_ram(buf->vaddr, buf->num_pages); - sg_free_table(&buf->sg_table); + sg_free_table(buf->dma_sgt); while (--i >= 0) { if (buf->dma_dir == DMA_FROM_DEVICE) set_page_dirty_lock(buf->pages[i]); @@ -333,14 +351,16 @@ static void *vb2_dma_sg_vaddr(void *buf_priv) BUG_ON(!buf); - if (!buf->vaddr) - buf->vaddr = vm_map_ram(buf->pages, - buf->num_pages, - -1, - PAGE_KERNEL); + if (!buf->vaddr) { + if (buf->db_attach) + buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf); + else + buf->vaddr = vm_map_ram(buf->pages, + buf->num_pages, -1, PAGE_KERNEL); + } /* add offset in case userptr is not page-aligned */ - return buf->vaddr + buf->offset; + return buf->vaddr ? buf->vaddr + buf->offset : NULL; } static unsigned int vb2_dma_sg_num_users(void *buf_priv) @@ -387,11 +407,110 @@ static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma) return 0; } +/*********************************************/ +/* callbacks for DMABUF buffers */ +/*********************************************/ + +static int vb2_dma_sg_map_dmabuf(void *mem_priv) +{ + struct vb2_dma_sg_buf *buf = mem_priv; + struct sg_table *sgt; + + if (WARN_ON(!buf->db_attach)) { + pr_err("trying to pin a non attached buffer\n"); + return -EINVAL; + } + + if (WARN_ON(buf->dma_sgt)) { + pr_err("dmabuf buffer is already pinned\n"); + return 0; + } + + /* get the associated scatterlist for this buffer */ + sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir); + if (IS_ERR(sgt)) { + pr_err("Error getting dmabuf scatterlist\n"); + return -EINVAL; + } + + buf->dma_sgt = sgt; + buf->vaddr = NULL; + + return 0; +} + +static void vb2_dma_sg_unmap_dmabuf(void *mem_priv) +{ + struct vb2_dma_sg_buf *buf = mem_priv; + struct sg_table *sgt = buf->dma_sgt; + + if (WARN_ON(!buf->db_attach)) { + pr_err("trying to unpin a not attached buffer\n"); + return; + } + + if (WARN_ON(!sgt)) { + pr_err("dmabuf buffer is already unpinned\n"); + return; + } + + if (buf->vaddr) { + dma_buf_vunmap(buf->db_attach->dmabuf, buf->vaddr); + buf->vaddr = NULL; + } + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); + + buf->dma_sgt = NULL; +} + +static void vb2_dma_sg_detach_dmabuf(void *mem_priv) +{ + struct vb2_dma_sg_buf *buf = mem_priv; + + /* if vb2 works correctly you should never detach mapped buffer */ + if (WARN_ON(buf->dma_sgt)) + vb2_dma_sg_unmap_dmabuf(buf); + + /* detach this attachment */ + dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach); + kfree(buf); +} + +static void *vb2_dma_sg_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf, + unsigned long size, enum dma_data_direction dma_dir) +{ + struct vb2_dma_sg_conf *conf = alloc_ctx; + struct vb2_dma_sg_buf *buf; + struct dma_buf_attachment *dba; + + if (dbuf->size < size) + return ERR_PTR(-EFAULT); + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + buf->dev = conf->dev; + /* create attachment for the dmabuf with the user device */ + dba = dma_buf_attach(dbuf, buf->dev); + if (IS_ERR(dba)) { + pr_err("failed to attach dmabuf\n"); + kfree(buf); + return dba; + } + + buf->dma_dir = dma_dir; + buf->size = size; + buf->db_attach = dba; + + return buf; +} + static void *vb2_dma_sg_cookie(void *buf_priv) { struct vb2_dma_sg_buf *buf = buf_priv; - return &buf->sg_table; + return buf->dma_sgt; } const struct vb2_mem_ops vb2_dma_sg_memops = { @@ -404,6 +523,10 @@ const struct vb2_mem_ops vb2_dma_sg_memops = { .vaddr = vb2_dma_sg_vaddr, .mmap = vb2_dma_sg_mmap, .num_users = vb2_dma_sg_num_users, + .map_dmabuf = vb2_dma_sg_map_dmabuf, + .unmap_dmabuf = vb2_dma_sg_unmap_dmabuf, + .attach_dmabuf = vb2_dma_sg_attach_dmabuf, + .detach_dmabuf = vb2_dma_sg_detach_dmabuf, .cookie = vb2_dma_sg_cookie, }; EXPORT_SYMBOL_GPL(vb2_dma_sg_memops); -- 2.7.4